The word Halloween is first attested in the 16th century and represents a Scottish variant of the fuller All-Hallows-Even ("evening"), that is, the night before All Hallows Day.

Trick-or-treating is a customary celebration for children on Halloween. Children go in costume from house to house, asking for treats such as candy or sometimes money, with the question, "Trick or treat?". In Scotland and Ireland, Guising — children disguise in costume going from door to door for food or coins.

Children dress as supernatural figures such as monsters, ghosts, skeletons, witches, and devils. Over time, the costume selection started to include popular characters from fiction, celebrities, and generic archetypes such as ninjas and princesses.

There are several games traditionally associated with Halloween. One of them is dunking or apple bobbing, in which apples float in a tub or a large basin of water and the participants must use their teeth to remove an apple from the basin. A variant of dunking involves kneeling on a chair, holding a fork between the teeth and trying to drop the fork into an apple. Another common game involves hanging up sweets and candy by strings; these must be eaten without using hands while they remain attached to the string,.

Another game/superstition that was enjoyed in the early 1900s involved walnut shells. People would write fortunes in milk on white paper. After drying, the paper was folded and placed in walnut shells. When the shell was warmed, milk would turn brown therefore the writing would appear on what looked like blank paper. Folks would also play fortune teller. In order to play this game, symbols were cut out of paper and placed on a platter. Someone would enter a dark room and was ordered to put her hand on a piece of ice then lay it on a platter. Her "fortune" would stick to the hand.

The telling of ghost stories and viewing of horror films are very common on Halloween. Episodes of television series and Halloween-themed specials (with the specials usually aimed at children) are commonly aired on or before the holiday, while new horror films are often released theatrically before the holiday to take advantage of the atmosphere.